High light extraction efficiency solid state light sources

US7932534B2 · kind B2 · utility

Assignees

• Sinmat, Inc. · US
• University of Florida Research Foundation, INC. · US

Inventors

• Rajiv Singh · Natick, US
• Purushottam Kumar · Hillsboro, US
• Deepika Singh · Gainesville, US

Key dates

• Filing date: Jun 9, 2010
• Grant date: Apr 26, 2011
• Expiry date: Jun 9, 2030

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10K50/858

Abstract

A solid state light source includes a substrate having a top surface and a bottom surface, and at least one optically active layer on the top surface of the substrate. At least one of the top surface, the bottom surface, the optically active layer or an emission surface on the optically active layer includes a patterned surface that includes a plurality of tilted surface features that have a high elevation portion and a low elevation portion that define a height (h), and wherein the plurality of tilted surface features define a minimum lateral dimension (r). The plurality of tilted surface features provide at least one surface portion that has a surface tilt angle from 3 to 85 degrees. The patterned surface has a surface roughness <10 nm rms, and h/r is ≧0.05.